Summary

• implement strided and grouped geqrf_batch, orgqr_batch, and ungqr_batch for buffer and USM APIs
• use rocSOLVER 64-bit batched geqrf entry points on rocSOLVER 3.26+, with a legacy fallback
• preserve legacy APIs for orgqr/ungqr, which have no 64-bit rocSOLVER entry points
• make grouped USM copy and cleanup dependencies explicit and add the corresponding scratchpad queries

Extracted from #767 for focused review. Depends on #778 for rocSOLVER version detection; until that PR merges, this branch intentionally includes its foundation commit.

Test plan

• clang-format 19.1 check
• git diff --check
• rocSOLVER backend build for gfx90a
• focused runtime tests on MI210 with ONEAPI_DEVICE_SELECTOR=hip:*: 40 passed
• focused compile-time tests on MI210 with ONEAPI_DEVICE_SELECTOR=hip:*: 40 passed

The legacy pre-3.26 fallback is retained for compatibility; the local ROCm 7.1 installation exercises the 64-bit geqrf path.